The present invention relates to a laminated electronic component, a laminated duplexer and a communication device mainly mounted on a high frequency radio device such as a cellular phone.
With miniaturization of communication devices, laminated electronic components are being used as high frequency devices in recent years. With reference to the attached drawings, an example of the above-described conventional laminated electronic component will be explained below.
FIG. 3 shows an exploded perspective view of a conventional electronic part. As shown in FIG. 3, the laminated electronic component comprises dielectric layer 301 to dielectric layer 308 placed one atop another. A grounding electrode 309 is placed on the dielectric layer 301 and capacitor electrode 310 is placed on the dielectric layer 302. Furthermore, strip lines 311 and 312 are placed on the dielectric layer 303 and connected at a connection point 313.
A capacitor electrode 314, a grounding electrode 315, a capacitor electrode 316 and a grounding electrode 317 are placed on dielectric layers 304, 305, 306 and 307, respectively. Furthermore, the capacitor electrode 310 is connected to a connection point 318 of the strip line 311 via a via hole 322 and the capacitor electrode 314 is connected to the connection point 313 via a via hole 323. Furthermore, the capacitor electrode 316 is connected to a connection point 319 of the strip line 312 via a via hole 324.
The grounding electrodes 315 and 317 are connected to the grounding electrode 309 via an external electrode 320 formed on one side of the laminated electronic component, and the external electrode terminals of the circuit form an input electrode and output electrode by extending one end of the strip lines 311 and 312 to the end face of the laminated electronic component and connecting them to the external electrode 321 formed on the sides of the laminated electronic component. However, for simplicity of explanations, the positions of the via holes in the figure are schematically shown with dotted line on the exploded perspective view in principle.
Then, FIG. 23 shows another example of a perspective view of a conventional laminated electronic component.
In FIG. 23, the laminated electronic component 3901 is constructed of a laminated body 3902 formed of a plurality of laminated dielectric sheets and external electrodes 3903. The inner layer of the laminated body 3902 contains at least one inner circuit (not shown) provided with input/output terminals and at least one inner grounding electrode (not shown).
On at least one side of the laminated body 3902, the external electrodes 3903 are formed and these external electrodes 3903 are electrically connected to the input/output terminals of the inner circuit and the inner grounding electrode respectively. Here, suppose the one electrode connected to the input/output terminals of the inner circuit is an external electrode 3903a and the other electrode connected to the inner grounding electrode is an external electrode 3903b. 
The external electrodes 3903a and 3903b are formed by applying a metal film to specific locations of the sides of the laminated body 3902 and all external electrodes are formed extending from the top surface to the bottom surface occupying a wide range of area.
However, in the case of the conventional configuration shown in FIG. 3, an input electrode, output electrode and grounding electrode exist as external electrodes on the sides of the laminated electronic component including a plurality of circuits, and therefore there is a plurality of external electrodes formed on the sides of the laminated electronic component, which reduces the area occupied by the grounding electrode. Therefore, it is not possible to secure a sufficient area for the grounding electrode with these external electrodes alone, causing a problem that electric grounding strength is weakened. The electric grounding strength means an electric grounding state and is also simply called grounding strength. Further, The ideal electric grounding state is the state where the electric potential is zero. Accordingly, xe2x80x9cgrounding strength is weakxe2x80x9d means the state apart from the ideal grounding state, and xe2x80x9cgrounding strength is strongxe2x80x9d means the state close to the ideal grounding state.
Here, the grounding electrode refers to an electrode to be connected to a predetermined grounding surface on a motherboard (not shown) on which the laminated electronic component is to be mounted by means of soldering, etc.
On the other hand, in the case of the conventional laminated electronic component shown in FIG. 23, the external electrode 3903a electrically connected to the input/output terminals of the inner circuit and the external electrode 3903b electrically connected to the inner grounding electrode have almost the same shape and are formed extending from the top surface to the bottom surface of the laminated body 3902 occupying a wide range of area.
For this reason, especially when the area of the external electrode 3903a electrically connected to the input/output terminals of the inner circuit is large, parasitic components such as a conductance component or inductance component are generated especially in the external electrode 3903a of these external electrodes 3903, leading to deterioration of characteristics when the device is used for a high frequency area.
Especially, when used as a laminated filter, etc. that handles an input signal of 1 GHz or greater, the above-described conventional laminated electronic component shown in FIG. 3 and FIG. 23 has the problem that the high frequency characteristic of the filter circuit, etc., that is, the characteristic of selecting frequencies in a high frequency area deteriorates.
The present invention has been achieved in view of these problems of the above-described conventional laminated electronic component and it is an object of the present invention to provide a laminated electronic component capable of sufficiently securing a grounding electrode and increasing the grounding strength.
Further, in view of these problems of the above-described conventional laminated electronic component, it is another object of the present invention to provide a laminated electronic component with an excellent characteristic of selecting frequencies in a high frequency area.
One aspect of the present invention is a laminated electronic component comprising:
a dielectric layer A provided with a first shield electrode on one principal plane;
a dielectric layer C which is a dielectric layer indirectly placed above said dielectric layer A, provided with a second shield electrode on one principal plane;
a dielectric layer D whose at least one principal plane is exposed outside;
a dielectric layer B which is placed between said dielectric layer A and said dielectric layer C, and includes an inner circuit; and
a first grounding electrode provided on the other principal plane of said dielectric layer A or said one principal plane of said dielectric layer D,
wherein a via hole is provided in at least one of said dielectric layer A or said dielectric layer D,
said first shield electrode and said second shield electrode are electrically connected, and
said first grounding electrode and said first shield electrode are electrically connected through via holes provided on said dielectric layer A or said first grounding electrode and said second shield electrode are electrically connected through via holes provided on said dielectric layer D.
Another aspect of the present invention is the laminated electronic component, comprising an end face electrode provided on one side of said laminated electronic component to electrically connect said first shield electrode and said second shield electrode.
Still another aspect of the present invention is the laminated electronic component, wherein said dielectric layer B includes a resonator electrode as said inner circuit,
said laminated electronic component is provided with a first terminal electrode connected to said resonator electrode,
said end face electrode is a second grounding electrode to be connected to a predetermined grounding surface on a substrate on which said laminated electronic component is to be mounted, and
said first terminal electrode is provided on sides of said dielectric layer A to dielectric layer D surrounded by said second grounding electrode or electrically connected to said second grounding electrode.
Yet still another aspect of the present invention is the laminated electronic component, wherein said dielectric layer B further includes a coupling electrode as said inner circuit, facing part of said resonator electrode,
said laminated electronic component is provided with a second terminal electrode connected to said coupling electrode, and
said second terminal electrode is (1) formed on said other principal plane of said dielectric layer A and/or said one principal plane of dielectric layer D in such a way that said second terminal electrode is not electrically connected to said first grounding electrode, and (2) electrically connected to said coupling electrode through a via hole different from said via hole.
Still yet another aspect of the present invention is the laminated electronic component, wherein said resonator electrode is constructed of a transmission line.
A further aspect of the present invention is the laminated electronic component, wherein said first grounding electrode is formed like either a mesh, band or spider""s web.
A still further aspect of the present invention is the laminated electronic component, wherein said coupling electrode is constructed of a transmission line.
A yet further aspect of the present invention is the laminated electronic component, wherein said coupling electrode is an inter-stage coupling capacitor electrode constructed of a transmission line.
A still yet further aspect of the present invention is a laminated duplexer comprising:
a transmission filter using the laminated electronic component; and
a reception filter using the laminated electronic component.
An additional aspect of the present invention is a communication device comprising:
a laminated filter using the laminated electronic component; and/or
the laminated duplexer.
The above-described configuration forms via holes on the dielectric layer on the bottom surface or top surface, connects a shield electrode and grounding electrode via a via hole, thus making it possible to secure a large grounding area irrespective of whether there are external electrodes on the sides of the laminated electronic component or not and increase the grounding strength.
A still additional aspect of the present invention is the laminated electronic component, comprising an external terminal electrode which is connected to said inner circuit and has a first height from the bottom surface to the top surface of said laminated electronic component,
wherein said end face electrode (1) is a second grounding electrode to connect to a predetermined grounding surface of a substrate on which said laminated electronic component is to be mounted and (2) has a second height from the bottom surface to the top surface of said laminated electronic component, and
said first height is different from said second height.
A yet additional aspect of the present invention is the laminated electronic component, wherein said first height from the bottom surface of said laminated body of said external terminal electrode is smaller than said second height from the bottom surface of said laminated body of said second grounding electrode.
A still yet additional aspect of the present invention is the laminated electronic component, wherein said second grounding electrode is provided extending from the top surface to the bottom surface of said laminated body.
A supplementary aspect of the present invention is the laminated electronic component, comprising an external shield electrode connected to said second grounding electrode,
wherein said external shield electrode is provided on the top surface of said laminated body.
A still supplementary aspect of the present invention is the laminated electronic component, comprising a lead-out side electrode connected to said shield electrode,
wherein said lead-out side electrode is provided extending at least from the top surface of said laminated body to the area on the side of said laminated body where said external terminal electrode is formed, and
the part provided on the side of said laminated body is placed higher than said external terminal electrode viewed from the bottom surface of said laminated body.
A yet supplementary aspect of the present invention is the laminated electronic component, wherein said lead-out side electrode is connected to said external shield electrode.
A still yet supplementary aspect of the present invention is the laminated electronic component, wherein said second grounding electrodes are placed on both sides of said external terminal electrode.
Another aspect of the present invention is
the laminated electronic component; comprising a plurality of said external terminal electrodes,
wherein said second grounding electrode is placed between said external terminal electrodes.
Still another aspect of the present invention is the laminated electronic component, wherein said lead-out side electrode is connected to at least one of said second grounding electrodes.
Yet still another aspect of the present invention is the laminated electronic component, wherein the distance between said external terminal electrode and said second grounding electrode placed next to said external terminal electrode is equal to or greater than the electrode width of said external terminal electrode.
Still yet another aspect of the present invention is the laminated electronic component, wherein said external terminal electrode and said second grounding electrode are buried in said laminated body or exposed outside said laminated body.
A further aspect of the present invention is the laminated electronic component, wherein said dielectric layer includes a crystal phase and glass phase,
said crystal phase includes at least one of Al2O3, MgO, SiO2 and ROa (R is at least one element selected from La, Ce, Pr, Nd, Sm and Gd, and a is a numerical value stoichiometrically determined according to the valence of said R).
A still further aspect of the present invention is the laminated electronic component wherein said dielectric layer includes Bi2O3, Nb2O6 as main components.
A yet further aspect of the present invention is a communication device, characterized by using the laminated electronic component.
The above-described laminated electronic component of the present invention is characterized in that the height of the external electrode connected to the input/output terminals of the at least one inner circuit is smaller than the height of the external grounding electrode connected to at least one shield electrode (inner grounding electrode).
A still yet further aspect of the present invention is a laminated electronic component comprising:
a laminated body that integrates a plurality of laminated dielectric sheets;
an inner circuit provided on the principal plane of a plurality of dielectric sheets within said laminated body;
a grounding electrode provided on the principal plane of a plurality of dielectric sheets within said laminated body;
a first via hole that penetrates the whole or part of said laminated body and electrically connects the grounding electrodes provided on the principal plane of said plurality of dielectric sheets;
a second via hole that penetrates the whole or part of said laminated body and electrically connects the inner circuits provided on the principal plane of said plurality of dielectric sheets; and
an input terminal and output terminal electrically connected to said second via hole,
wherein at least one of said grounding electrodes is provided as an exposed grounding electrode which is exposed outside from the principal plane of the dielectric sheet in bottom layer and/or top layer of said dielectric layer, and
said input electrode and said output electrode are provided on both sides of said exposed grounding electrode on the same plane as the plane on which said exposed grounding electrode is provided.
An additional aspect of the present invention is the laminated electronic component, wherein said grounding electrodes other than said exposed grounding electrode have no exposed parts outside said laminated electronic component.
A still additional aspect of the present invention is the laminated electronic component, wherein said plurality of dielectric sheets has at least a first dielectric sheet and second dielectric sheet,
said plurality of grounding electrodes has at least a first grounding electrode provided on the principal plane of said first dielectric sheet and a second grounding electrode provided on the principal plane of said second dielectric sheet,
said second dielectric sheet is placed between said first grounding electrode and said second grounding electrode, and
said first via hole at least penetrates said first dielectric sheet and/or said second dielectric sheet and electrically connects said first and second grounding electrodes.
A yet additional aspect of the present invention is the laminated electronic component, wherein said second dielectric sheet is provided in a layer superior to said first dielectric sheet.
A still yet additional aspect of the present invention is the laminated electronic component, wherein at least one dielectric sheet with said inner circuit provided on the principal plane is placed between said first dielectric sheet and said second dielectric sheet.
A supplementary aspect of the present invention is the laminated electronic component., wherein said first dielectric sheet and said second dielectric sheet are directly laminated together.
A still supplementary aspect of the present invention is the laminated electronic component, wherein said plurality of dielectric sheets includes at least a third dielectric sheet,
said plurality of grounding electrodes includes at least a third grounding electrode provided on the principal plane of said third dielectric sheet, and
said first via hole at least penetrates said third dielectric sheet and electrically connects said third dielectric sheet and said exposed grounding electrode.
A yet supplementary aspect of the present invention is the laminated electronic component, wherein at least one dielectric sheet with said inner circuit provided on the principal plane is placed between said third dielectric sheet and said dielectric sheet provided with said exposed grounding electrode.
A still yet supplementary aspect of the present invention is the laminated electronic component, wherein said third dielectric sheet and the dielectric sheet provided with said exposed grounding electrode constitute the same dielectric sheet.
Another aspect of the present invention is the laminated electronic component, wherein said dielectric sheet has a thickness of 5 to 50 xcexcm.
Still another aspect of the present invention is the laminated electronic component, wherein said dielectric sheet is made of at least a crystal phase and a glass phase,
said crystal phase contains at least one of Al2O3, MgO, SiO2 and ROa (R is at least one element selected from La, Ce, Pr, Nd, Sm and Gd, and a is a numerical value stoichiometrically determined according to the valence of said R).
Yet still another aspect of the present invention is the laminated electronic component, wherein said dielectric sheet contains Bi2O3 and Nb2O6.
Still yet another aspect of the present invention is a high frequency radio device, mounting the laminated electronic component.
The above-described laminated electronic component of the present invention is, for example, an electronic part comprising a laminated body integrating a plurality of dielectric sheets placed one atop another and a plurality of inner circuits provided with an input electrode and an output electrode and a plurality of grounding electrodes inserted in the inner layer of the above-described laminated body, wherein a first grounding electrode is formed on the bottom surface of the above-described electronic part, a second grounding electrode is formed in the inner layer of the above-described electronic part and the above-described first grounding electrode and the above-described second grounding electrode are connected through at least two via holes.